Magnetic resonance (MR) imaging is a known technology that can produce images of the inside of an examination subject without radiation exposure. In a typical MR imaging procedure, the subject is positioned in a strong, static, homogeneous base magnetic field B0 (having a field strength that is typically between about 0.5 Tesla and 3 Tesla) in an MR apparatus, so that the subject's nuclear spins become oriented along the base magnetic field. Radio-frequency (RF) excitation pulses are directed into the examination subject to excite nuclear magnetic resonances, and subsequent relaxation of the excited nuclear magnetic resonances can generate RF signals. Rapidly switched magnetic gradient fields can be superimposed on the base magnetic field, in various orientations, to provide spatial coding of the RF signal data. The RF signal data can be detected and used to reconstruct images of the examination subject. For example, the acquired RF signal data are typically digitized and stored as complex numerical values in a k-space matrix. An associated MR image can be reconstructed from the k-space matrix populated with such values using a multi-dimensional Fourier transformation.
Magnetic resonance imaging (MRI) can be used in certain interactive procedures, such as precise real-time MR-guided needle placement (e.g. for tissue biopsy sampling, infiltration, precise placement of a thermal applicator such as a radio frequency (RF) needle or the like, etc.). In such MRI-guided (or MRI-assisted) procedures, it may be essential to control the MRI system from within the scanner room. Typically, the commands needed for such interactive MRI control during a procedure can be a limited of commands that may be applied several times during a procedure. For example, in some MRI-assisted needle placement procedures, a dynamic control of the imaging plane for monitoring of the needle trajectory in real time can be used. This monitoring can be achieved by updating or varying the imaging plane between image acquisitions based on the position and/or orientation of the needle. Additional commands may be desirable during such procedures, e.g., to control movement of the patient table movement or for control of a robotic device.
The usage of conventional control interfaces such as e.g., a keyboard, a computer mouse, etc. for the control of the MRI scanner and associated devices can be cumbersome during a procedure. Further, the presence and use of such interface devices may impact sterility of the room in which the MRI-assisted procedure is being performed. Operation of such conventional computer interfaces by the interventionist may also be incompatible with workflow requirements and/or may raise safety concerns during procedures, as they typically require the interventionist to be within reach of a mouse/keyboard. Manual operation of a keyboard or mouse can also be inconvenient in certain procedures, e.g., if the interventionist wishes to control aspects of the MRI scanner and/or display while holding one or more instruments.
In conventional MRI-assisted procedures, the interventionist may verbally instruct a technician in the console room to control aspects of the imaging system during. Because MRI systems are typically very loud, such communication may be supported by a communication system that includes special noise-cancelling headphones and microphones. Alternatively the interventionist can provide operational instructions by making gestures towards the technician to indicate what action is to be taken. However, such signaling approach requires an understanding between the interventionist and the technician of the meaning of any gestures, and proper interpretation of such signals, which may be distracting to the interventionist. The reliability of such visual communication of commands can also be inconsistent if different technicians work with different interventionists.
Additionally, activating certain commands during MRI-assisted procedures may be undesirable or raise safety concerns. For example, moving the patient table while a needle is inserted can be dangerous and/or impair the effectiveness of an insertion procedure. During such procedures, improved control and verification of system commands by an interventionist may be desirable.
Accordingly, it would be desirable to have a system and method for controlling aspects of an MRI system during interactive imaging procedures that addresses some of the shortcomings described above.